Sources and probabilistic ecological-health risks of heavy metals in road dust from urban areas in a typical industrial city

Urban road dust (URD) is a primary source of pollutants in urban environments. The contamination of heavy metals (HMs) in URD from urban area of Xingtai, a typical industrial city in China, was evaluated using enrichment factor, geoaccumulation index, and Nemerow integrated enrichment factor, along with Monte Carlo simulation (MCS). The HM sources in the URD were apportioned using positive matrix factorization (PMF). We employed a combination of PMF and MCS to estimate the probabilistic ecological-health risks of source-specific HMs in the URD and to identify priority sources and pollutants for HMs pollution control in the URD. Compared to the background values, the URD had elevated Pb, Co, Cr, Cu, Zn, and Ba concentrations. The overall pollution levels and ecological risks of the HMs were heavy and moderate, respectively, and were mainly caused by Co. The potential carcinogenic risks posed by HMs in URD to residents, and their non-carcinogenic risks to children, cannot be overlooked. The HMs in the URD originated mainly from industrial, mixed, and atmospheric deposition sources, accounting for 28.8, 30.8, and 40.4% of the total HMs, respectively. Mixed and industrial sources were priority sources, and Co and Cr were priority control HMs in the URD.